Clean Beauty 'Experts' Want You To Believe Antiperspirant Causes Cancer. Here's What The Research Says. (2025)

In the late 90s, when email was still a novelty for many and before the term "fake news" had even made the news, an ominous message reportedly hit inboxes across America with a terrifying claim: using antiperspirant can cause breast cancer. As the story goes, the alarming missive declared that the active ingredients in most antiperspirant products—aluminum salts like aluminum chloride and aluminum zirconium tetrachlorohydrex glycine—are absorbed into the bloodstream, leading to carcinogenic changes.

The incendiary declaration—made against such a ubiquitous product—caused consumers to sweat. Aluminum had already dealt with its share of bad press—researchers in the 60s and 70s noticed that Alzheimer's disease patients had high levels of the metal in their brain, leading people to question their daily exposure from cooking pots, foils, soda cans, and antacids. So naturally, the antiperspirant email struck a chord. People already primed to panic about the ingredient started to forgo using antiperspirants, replacing them with natural odor-fighting alternatives.

And with that, natural deodorant became the O.G. poster child for what we now know as the clean beauty movement. Sweat-blocking aluminum salts and preservatives were replaced by plant extracts, essential oils, and other odor and perspiration absorbers like baking soda and charcoal. Today, you'll find natural deodorants on store shelves from coast to coast (the concept went mainstream when Schmidt's rolled out their solid sticks, the first and only natural deodorant to earn the organic Ecocert seal). By 2023, the market for natural deodorant was valued at over $81 million—and it's expected to grow to $162 million by 2031.

But was all that panic—and the millions of dollars made off it—justified?

A controversy begins

It's important to first understand how these products work. "Aluminum salt compounds are used to block sweat glands and reduce perspiration," says Amy B. Lewis, MD, an associate clinical professor of dermatology at Yale University School of Medicine and founder of Lewis Dermatology & Associates in New York City, and they're the only over-the-counter ingredient widely recognized to do so. They dissolve on your skin, seeping into pores where they create a plug-like effect so sweat can't get out. Most of the antiperspirants you'd buy at a drugstore chain contain 10% to 15% of the active ingredient, with clinical or extra-strength and prescription formulas hitting the 20% to 25% mark. Because antiperspirants affect a bodily function—in this case perspiration—they're regulated by the U.S. Food & Drug Administration as an over-the-counter drug.

In 1990, another study yet again demonstrated a potential link between aluminum-containing products and Alzheimer's disease, but it was ultimately deemed inconclusive due to its methodology (it relied on caregivers' reports of antiperspirant usage). Then came the infamous email. Where did it come from? Oddly enough, no one seems to know. It’s well-documented that the antiperspirant-breast cancer connection stems from this email hoax, but there’s no information about who sent it and who was targeted. "It’s a bit of an urban legend itself,” says Jules Cohen, MD, a medical oncologist at the Stony Brook Cancer Center in Stony Brook, New York. “The viral email suggested that chemicals in antiperspirant such as aluminum could be absorbed through small nicks in the skin caused by shaving,” he says. The theory was that it could get into the skin and affect estrogen receptors in breast cells.

More trouble came for traditional deodorants and antiperspirants when a small study in 2004 found parabens in breast tumors. This class of preservatives (methylparaben, ethylparaben, and propylparaben are a few examples) was widely used in personal care products, including those meant for underarm use. Parabens can act like a very weak version of estrogen in lab tests, and some researchers think they might slightly raise the risk of a type of breast cancer that responds to estrogen, says Dr. Cohen. But since the 2004 paper, no study has ever been able to prove conclusively that parabens cause cancer.

How did such weak science cause so many to suddenly change, or at least question, their hygiene habits? Location, location, location. "The theory linking antiperspirants to breast cancer gained traction because breast cancer often develops near the underarm area," says Raphael Cuomo, PhD, a clinical cancer epidemiologist at the UC San Diego School of Medicine. Fortunately, the panic spurred researchers to action. They wanted to find out if the reports had any validity.

The real deal: Are aluminum antiperspirants bad for you?

These products have been under scrutiny for decades. Type “aluminum antiperspirant” into PubMed, the online database maintained by the National Institutes of Health (NIH) that provides access to scientific studies, and there are almost 1,500 studies looking at the product between the years of 1990 and 2025. Let’s start with the basics: Does aluminum even get absorbed into the skin? According to a 2001 paper published in Food and Chemical Toxicology, a minimal amount—0.012% or four micrograms (mg)—may get absorbed by the skin after a single antiperspirant use. To put that into perspective, the average American eats 7 to 9 mg of aluminum a day, so antiperspirant use would only account for about 2.5% of our total intake.

Ok, so we know small amounts make their way into the body, but does it cause harm once it's there? Subsequent studies on Alzheimer's have failed to prove a link between the neurological disease and aluminum and according to the Alzheimer's Association, "Most experts believe aluminum does not pose a threat."

The aluminum-breast cancer link seems to be unfounded as well. "While the concerns about antiperspirants causing cancer were fueled by speculation and initial small studies, the majority of current research has not found a strong link between antiperspirants and breast cancer," says Dr. Lewis. A large case-control study in 2002, published in the Journal of the National Cancer Institute, looked at 1600 women—813 women with breast cancer and 793 without breast cancer—and found no link between the use of antiperspirants, shaving of the armpit, or both, and breast cancer. "More recent research, including a 2017 systematic review, has also failed to establish a causal link between aluminum, parabens, and breast cancer," adds Dr. Cuomo. "Major health organizations, including the FDA, European Food Safety Authority, and World Health Organization, have reviewed the data and do not classify aluminum as a known carcinogen, says Dr. Cuomo. And hot off the press: A 2025 review published in Current Medicinal Chemistry once again explored the topic and did not establish a causal connection between antiperspirant and breast cancer (the researchers did note that more larger-scale studies and rigorous methodologies are needed to validate past findings).

If you’re saying, “But what about those estrogen claims?” You can rest-easy knowing breast cancer experts aren’t concerned. When asked about a 2018 study that showed aluminum interferes with estrogen receptors in breast cancer cells, Dr. Cohen is quick to point out that it was an in vitro study (not done on a living organism). "Even if the results were robustly reproducible, it's a long way from in vitro laboratory studies to in vivo mouse studies with patient-derived xenografts [tissue taken from a patient and transplanted to a rodent for research purposes] to proving causality in actual breast cancer patients," he says. And if antiperspirants caused breast cancer, "Why wouldn't more males get breast cancer? he asks. (For the record, in 2024, over 310,000 women were estimated to be diagnosed with breast cancer compared to only 2,790 men.)

As for parabens, it’s a moot point these days, as they are rarely used in personal care products after that 2004 study—not because they were found to cause cancer but because of consumer demand to remove them. "Parabens are preservatives used to prevent bacterial growth in products," says Dr. Lewis. "They can mimic estrogen, but the research has shown that their effect is weak compared to natural estrogen in the body," she says. Studies, including the initial one in 2004, have been unable to link parabens to cancer conclusively, she says.

The concern that breast cancer is more common in the upper outer quadrant, near the armpit, because of antiperspirants is a bit of a red herring, too. "This area just naturally contains more breast tissue, so it would make sense that there would be an increase in the likelihood of cancer developing there," says Dr. Lewis. Plus, Dr. Cohen also points out that the breast drains to the axillary lymph nodes, not the reverse. "So, aluminum salts applied to the armpit skin don't really have a way of getting to the breast in the first place," he says

So...now what?

The overwhelming majority of scientists and doctors say the evidence shows no conclusive link between aluminum-based antiperspirants and health risks. However, if the small and inconclusive studies are enough to make you say, "But what if…", the good news is there are more aluminum-free options now than ever—from solids to paste-like formulas. "Like all 'clean beauty products,' using a more natural deodorant is a personal choice," says Dr. Lewis. "Just know, they may not stop the sweat as well, and they may be more expensive, but they will provide peace of mind if you're still worried."

You can also limit exposure by steering clear of clinical-strength formulas in favor of conventional antiperspirants with lower percentages of aluminum (again, typically 10% to 15% aluminum chloride).

The vilification and (possibly) vindication of aluminum is a cautionary tale and a reminder not to believe everything you read, especially in a forwarded email (or, these days, a social media post). It turns out that aluminum is not the pits for your health. But then again, the controversy led to a new category of underarm care products.

That part doesn’t stink.